Darkfield Microscopy

Digital Image Gallery

The Molecular Expressions gallery of darkfield illumination photomicrography contains a wide spectrum of images taken under a variety of conditions and utilizing many different specimens. Included in this unique gallery are specimens ranging from simple diatoms to fossilized dinosaur bones, insects, Moon rocks, and integrated circuits. Use the links below to navigate to the individual entries in the gallery.

Arachnoidiscus ehrenbergi - This spectacular darkfield photomicrograph of the diatom Arachnoidiscus ehrenbergi was captured on an Olympus microscope by Mortimer Abramowitz, senior microscopist at Olympus America. The specimen was illuminated with a high numerical aperture darkfield condenser with immersion oil placed between the microscope slide and the objective and condenser front lenses.

Basswood - Stained thin sections from this ornamental hardwood tree produce beautiful images under darkfield illumination. The American Basswood is one of the most treasured ornamental trees, having a tall, straight trunk and rounded crown. In the summer, basswood flowers bloom and fill the air with their fragrance as they attract bees to aid in pollination. Basswood is a hardwood that is well-suited for growth in rich and fertile soils of the Northeast United States.

Butterfly Wings - A network of scales covers most of the wing, giving it a beautiful array of colors produced either by pigmentation or through optical interference. The iridescent colors usually associated with butterfly wings arise from the small ridges on the scales, which interact with light causing constructive and destructive interference, much like that produced by a soap bubble.

Centipede Head - Poison claws greet our visitors to this image, which was mounted as a whole specimen and captured with darkfield illumination. Centipedes have segmented bodies with one pair of legs per segment. The head lacks legs but is still a segment with the poison claws acting as truncated and modified legs.

The Con Artist - This shady character was spotted lurking within the circuitry of a Hewlett-Packard microprocessor. The con artist was constructed in a series of small squares, much like a bitmap image. Methodology using these small squares is the safest technique that engineers have discovered for patterning these miniature doodles. The actual squares are really contacts (voids where a hole is produced in the dielectric medium) between two metal layers and appear as a series of slight dents in the surface of the chip.

Cretaceous Period Dinosaur Fossil - An unusual photomicrograph of a mineralized dinosaur fossil showing jagged teeth-shaped structures. Fossilized dinosaur bones come in a variety of forms depending on how they have been petrified. Most dinosaur bones have been petrified with calcium, which yields a stony appearance and texture. Agatized bones are petrified with silica, or quartz crystals, giving them a colorful, glassy appearance. Fossilization occurs when hard parts from a dead plant or animal are buried quickly in sediments and exposed to mineralized solutions over long periods of time.

Dictydium cancellatum - This beach-ball shaped fungus was captured on film with darkfield illumination of a stained specimen. Mycologists often study slime molds because their fruiting body parts are often similar in appearance to common fungi. These tiny creatures are commonly found in rotted logs and decaying plant matter, where there is an abundant supply of moisture and bacteria.

The Dream - We captured this image of a hand holding an inside straight (poker) on the surface of a Digital CVAX microprocessor. For more information and digital images of silicon artwork found on integrated circuits, visit the Silicon Zoo gallery, also located on the Molecular Expressions website.

Flea Head - Appearing like a creature out of the movie "Aliens", this close-up of a flea head reveals the cluster of piercing and sucking mouth parts used to feed on animals. Fleas are a relentless summer pest throughout the world, but some species can persist through the winter. These hard-bodied insects (difficult to crush with the bare hand) grow to a size between 1/16 and 1/8 inch by sucking blood from their hosts.

Insect Antenna - This captivating photomicrograph illustrates the beauty of a simple insect antenna. Insect antennae are exterior sensory structures that aid these tiny creatures in navigating through their environment in search of food and mates. Some of the more complex antennae are adapted to increase the surface area available to sensory cells that locate pheromones and other molecules related to the activities of insects.

Lapis Lazuli - Dominated by a rich brilliant blue color due to sulfur compounds, lapis lazuli has long been cherished as a spiritual stone and is useful in making beautiful jewelry. This beautiful mineral was first mined in Afghanistan thousands of years ago, and is very commonly used for making jewelry in the middle east and throughout the world. The best source for lapis is the mountains in remote Afghanistan, although the mineral is also found in Chile and in smaller quantities in Russia and other countries.

Liquid Crystalline DNA - DNA undergoes a series of liquid crystalline phase transitions in vivo, which serves to aid in compacting the long string-like molecule for storage within the cell. DNA is a very unusual molecule that is shaped like a very long piece of string. The diameter of the DNA molecule is about 25-30 Angstroms (about a billionth of an inch) while the length can exceed a thousand microns (0.025 inch) in some organisms. One of the major problems of molecular biology is how this giant molecule can be packaged into a cell or virus that is far smaller than the length of the DNA molecule.

Mink Fur - Prized by many for its beautiful rich fur, the mink coat is composed of mixture of hair sizes and textures. The mink is a semi-aquatic carnivorous mammal related to the weasel. Widely bred on farms for its thick rich brown fur, the mink is native to North America and Europe.

Moon Rock From Apollo 11 - Man's first mission to the Moon in July of 1969 resulted in the return of extraterrestrial material for scientists to examine. The astronauts who visited the Moon carefully collected 2,196 documented samples of lunar soils and rocks weighing a total of 382 kilograms (843 pounds) during approximately 80 hours of exploration. It is important to note that these samples were gathered from a harsh lunar environment that included wildly fluctuating temperatures in an almost complete vacuum, dangerous solar radiation, and the uncertainty of return to Earth due to equipment failure.

Mosquito Head and Proboscis - The business end of a male mosquito is captured with an Olympus digital camera under darkfield illumination. Mosquitoes are insects belonging to the Diptera order, along with their cousins, the true flies. They have two wings and their mouthparts form a long piercing-sucking proboscis, although in male mosquitoes the mouthparts are not suitable for piercing skin.

Quasicrystals - Discovered in 1984, these metallic "alloys" display unusual polyhedral symmetry not present in classical crystals. The quasicrystalline state was discovered in 1984 when researchers obtained electron diffraction patterns of an aluminum/manganese alloy that possessed sharp reflections and a 10-fold symmetry. Solution of the diffraction patterns revealed the presence of an icosohedral symmetry composed of a series of pentagonal and hexagonal shapes. Since then, many stable and meta-stable quasicrystals have been synthesized.

Sawdust - Tiny fragments of wood become a work of art as they are beautifully illuminated by darkfield microscopy. Much of the sawdust mixture is composed of hardened wood sap that is released during the production of sawdust. The complex structure of sawdust is formed by hardened sap that forms while the wood is being ripped and torn apart.

Silkworm Larva - Using a stained specimen, this darkfield photomicrograph illustrates the spiracle and trachea of a silkworm larva. The specimen is a whole mount, captured with a Nikon Optiphot microscope at 4x under darkfield illumination conditions using a swing-out top lens condenser and a 10-millimeter opaque light stop.